Certain winch designs have a basic requirement for a brake. The winch must be able to hold a load in place after the winching operation is completed. An important factor in designing such a unit is cost. Such a design might ideally incorporate a brake which would not react to centrifugal forces and therefore would not react to changes in motor speed. Simple disc brakes will accomplish that purpose. However, disc brakes are not compatible with a low-cost, compact winch unit intended for use in a variety of applications.
For maximum convenience and cost effectiveness, a brake housed inside a cable drum is particularly advantageous. A disadvantage of such an arrangement is that conventional approaches normally involve use of a brake which presents a centrifugal force problem. More specifically, a brake could be used with a one-way clutch so that the brake acts only in a cable out direction and with proper design a load can be held at rest. However, when a motor is powered in reverse for paying out cable, centrifugal forces normally fling brake pads outwardly, increasing the brake drag. As the motor speed increases, the drag increases as the square of the motor speed. Extra drag causes the drum to overheat excessively, the motor lugs down and runs too slowly and wastes far too much power which in turn produces considerable heat and unacceptable wear and tear on the components.